A magnitude 6.0 earthquake between New Zealand and Tonga has tricked sensors into thinking there was an even bigger quake just off the New Zealand coast.
The US Geological Survey says the tremor in the Kermadec Islands region, about 1000km northeast of New Zealand, struck about 4.16pm (1416 AEST) on Monday at a depth of about 325km.
It was about 112 kilometres from the nearest populated area at L’Esperance Rock.
The quake was strong enough to fool sensors in New Zealand, where GNS Science reported two quakes measuring 6.0 and 6.3 just off the North Island’s east coast about 4.20pm local time.
However, it quickly tweeted that they were a misreading.
Civil Defence was prompted to send out an earthquake advisory.
“Sometimes we do get events like that, it’s difficult for our network,” GNS Science duty seismologist Anna Kaiser told AAP.
Because two different waves arrived at separate times the sensors were tricked into thinking the single distant large event was actually two separate closer events, she said.